One example of an IC package processing and measuring system of this type is a laser marking system. Such a system is constituted by a combination of a laser marker that sequentially marks product number, date of manufacture, lot number, serial number, etc. onto a plurality of IC packages juxtaposed on a lead frame, using a laser beam, and an IC feed device that sequentially feeds IC packages in respect of a prescribed marking area of the laser marker by feed control of the lead frame on which the IC packages are mounted.
In such a laser marking system, the marking area of the laser marker is a region set up in the maximum region that can be scanned by the laser beam. Marking cannot be performed on IC packages positioned outside the marking area.
Recently however as a consequence of expansion of the marking area due to raising of the performance of the laser marker, improvement in the degree of circuit integration of IC packages fed into the marking area, and miniaturization of the IC packages, laser marking systems are being developed in which a plurality of IC packages can be fed (accommodated) into the marking area at once. Such systems are much more advantageous than systems in which only a single IC package can be fed into the marking area in point of view of processing efficiency, working time, and cost aspects.
However, in a laser marking system capable of feeding a plurality of IC packages into the marking area, due to the relationship between the size or mode of arrangement of the marking area and IC packages, in some cases, the ratio between the number N of ICs carried on a single lead frame and the number n of IC packages that can be accommodated in the marking area (N/n) is not an integer ratio, giving rise to a margin M.
For example, in the case where N=10 and n=4, a margin M=2 is produced. Specifically, in this case, when marking is performed for the first time, of the ten IC packages, marking is performed on a first group of four packages; feeding of the lead frame is performed and the next four IC packages are positioned in the marking area. Marking is then carried out for the second time and the second group of four IC packages are marked. After the, feeding of the lead frame is again performed. At this stage, only the last two IC packages are positioned in the marking area, so an incomplete group is left.
Consequently, in such a case, if the laser marker is controlled in the same way as in the first and second marking, the time required for this ineffective processing represents wasted time that does not contribute to the processing operation; this results in a useless increase in processing and measuring time and gives rise to the inconvenience that the feed portion of the IC feed device and/or the IC packages may be damaged by the laser beam.
Also, conventionally, as the feed distance data of the IC packages employed in the IC feed device, or the position data of the IC packages in the marking area employed by the laser marker, data calculated beforehand were input by the operator manually. There was therefore the problem that not only was it necessary to effect new calculations and input every time the type of the IC package or the type of the lead frame was altered, but also operating efficiency was poor and operation was complicated.
Also, in such a system, if some abnormality of the laser marker or IC feed device occurs during operation of the system, if the mechanism is stopped during the course of the marking process, the lead frame will contain both already-marked IC packages and IC packages awaiting marking. Consequently, in such cases, when restarting the marking operation after repairing the system, it is necessary to perform marking only in respect of the IC packages that are awaiting marking, by designating the IC packages that have not already been marked.
However, in such cases, conventionally, the operator had to designate the required IC packages by re-inputting the position data of the IC packages awaiting marking to the laser marker. This had the problem of being complicated and inefficient.
With the foregoing in view, it is an object of the present invention to provide a system and a method for IC package processing and measurement in which, in cases where an incomplete number of unprocessed IC packages are fed into the processing and measuring area, the processing and measuring action is only executed on the incomplete number of unprocessed IC packages, thereby raising operating efficiency and avoiding damage of the mechanism.
A further object of the present invention is to provide a system and a method for IC package processing and measurement in which ease of operation is increased and operating time is reduced.